I had a player that built the Shuriken weapon from Tinker's Construct, and any time he uses it to kill a compressed mob the server crashes. The modpack in use is The World of Arrakis https://mods.curse.com/modpacks/minecraft/278667-the-world-of-arrakis

The crash that is generated is https://pastebin.com/iXEx4FgZ

The pack version in use is Beta 0.3 (Current)

here is the stats and info on the weapon that was used and was crashing the server when killing compressed mobs.

i have been using a normal sword from tinkers to kill with to, but never crashed then